Sequential Extraction of Natural Surface Coatings: Comparison with Single Stage Extraction and Its Application in Investigating Adsorption Characteristics of Surface Coating Components for Metals

Multistage sequential extraction with different sequences was applied to extracting natural surface coa tings（NSCs）, and the results were compared with those by single stage extraction technique. The optimal sequential extraction scheme with the best performance was selected and incorporated into the method of selective extraction followed by adsorption and statistic analyses to study the adsorption parameters of Fe oxides, Mn oxides and organic matters in NSCs for Pb and Cd, to validate the applicability of the sequential extraction scheme. The Langmuir ad sorption parameters of each component of surface coating estimated according to the adsorption data of single stage extraction of NSCs were all similar to those of sequential extraction of NSCs, and the maximum difference between the metal adsorption abilities of the components estimated via the two extraction techniques was only about 20%, in dicating that either extraction techniques could be used. The optimal sequential extraction scheme obtained was first extracted with NH2OH·HCl, then with Na2S2O4, and finally with oxalic acid.

Single and Sequential Extraction of Copper by Different Extractants from Different Peat Soil Samples of Bangladesh

A comprehensive in vitro study on single and sequential extraction methods for Cu exraction by different extractants of distinct chemical nature from some peat soils of Bangladesh was conducted to assess the pattern of metal-extractability in drying and wetting sequences. Samples were collected from peat basins of two different districts of Bangladesh (Gopalgonj and Bagerhat) and an incubation study was designed and conducted in which soils were incubated to three alternate drying and wetting cycles for 21 days. Single and sequentially extracted Cu ions in all three cycles and by all three selective extractants were compared. Maximum amount of Cu was extracted in drying days and 1M HCl extracted the largest proportion of Cu from all the soils in each incubation time. Conversely, 1M NH4Cl was the least effective extractant for extracting Cu by both single and sequential process in either day of incubation. Considerable amount of Cu was extracted by 0.005 M DTPA in dry periods. In general, single extraction was found to be more effective in extracting Cu in the alternate drying and wetting cycles from the peat soil samples except for 1M HCl in initial drying days.

Human Ear Image Recognition Method Using PCA and Fisherface Complementary Double Feature Extraction

Ear recognition is a new kind of biometric identification technology now.Feature extraction is a key step in pattern recognition technology,which determines the accuracy of classification results.The method of single feature extraction can achieve high recognition rate under certain conditions,but the use of double feature extraction can overcome the limitation of single feature extraction.In order to improve the accuracy of classification results,this paper proposes a new method,that is,the method of complementary double feature extraction based on Principal Component Analysis(PCA)and Fisherface,and we apply it to human ear image recognition.The experiment was carried out on the ear image library provided by the University of Science and Technology Beijing.The results show that the ear recognition rate of the proposed method is significantly higher than the single feature extraction using PCA,Fisherface,or Independent component analysis(ICA)alone.

Progress on traditional Chinese medicine in improving hepatic fibrosis through inhibiting oxidative stress

Hepatic fibrosis is a common pathological process that occurs in the development of various chronic liver diseases into cirrhosis and liver cancer,characterized by excessive deposition of the extracellular matrix.In the past,hepatic fibrosis was thought to be a static and irreversible pathological process.In recent years,with the rapid development of molecular biology and the continuous in-depth study of the liver at the microscopic level,more and more evidence has shown that hepatic fibrosis is a dynamic and reversible process.Therefore,it is particularly important to find an effective,simple,and inexpensive method for its prevention and treatment.Traditional Chinese medicine(TCM)occupies an important position in the treatment of hepatic fibrosis due to its advantages of low adverse reactions,low cost,and multi-target effectiveness.A large number of research results have shown that TCM monomers,single herbal extracts,and TCM formulas play important roles in the prevention and treatment of hepatic fibrosis.Oxidative stress(OS)is one of the key factors in the occurrence and development of hepatic fibrosis.Therefore,this article reviews the progress in the understanding of the mechanisms of TCM monomers,single herbal extracts,and TCM formulas in preventing and treating hepatic fibrosis by inhibiting OS in recent years,in order to provide a reference and basis for drug therapy of hepatic fibrosis.